For the uninitiated, a baritone is a guitar tuned a 5th below a normal guitar. So, a standard guitar is tuned E to e and a baritone has an extended scale (neck length) to tune down to B to b, which places it right between a guitar and a bass. It’s a nice way to extend your range and add something new to the arsenal.
The tune is “Never Going Back Again” by Fleetwood Mac. Years ago, I heard Buckingham perform the song in a slowed-down and tuned-down version with a new solo section. This was in the days of Napster so I burned it to CD and took it to my teacher at the time. He gave it a listen and showed me what was going on. It was tuned down to Bb and was deep, rumbly, and kinda buzzy. It was also a nice complement to the spiteful lyrics that were previously balanced by the up tempo feel of the original recording. Lesson? Sometimes you just need to change the tuning, the key, or the guitar for a new idea.